Receptor-mediated cascade of phospholipid metabolism was further analyzed. This phospholipid cascade involves interaction of receptors with specific ligands, activation of phospholipid methylation, influx of Ca2+, activation of kinases, phosphorylation of phospholipase inhibitory protein (lipomodulin), activation of phospholipases, release of arachidonate. Lipomodulin has been purified from conditioned media of neutrophils treated with glucocorticoids and a monoclonal antibody against this protein has been isolated. This protein can inhibit arachidonate release from various cells and anti-lipomodulin antibody can block the effects of lipomodulin.